RAR archive of 38.5 MB containing ASUS motherboard repair guide material focused on power sequencing, going by the name. Such guides explain the order in which standby and main rails come up, the enable and power-good signals involved, and typical failure points. That makes it useful for diagnosing boards that do not power on or that stop partway through start-up. The archive opens with WinRAR or 7-Zip. Specific models covered are not stated in the name, so check the contents against your board.
The button opens the matching file on RM Schematics, or a source page if it is not catalogued there yet. The original attachment is from @videocard_notebook_resistance. Enginerys does not host this file.
How to open a .rar file
Compressed archive — the usual wrapper for a schematic + boardview pair or a BIOS + EC set.